With the advent of induced draft combustion apparatus for furnaces and the increased cost of fuel, in particular natural gas, continued research and development is being made to provide improved control systems and components. Such a system is shown in a copending application by the same inventor, Thomas S. Jaeger, entitled CONTROL SYSTEM FOR CONTROLLING THE FUEL/AIR RATIO OF COMBUSTION APPARATUS, Ser. No. 509,833, now U.S. Pat. No. 4,468,192 issued Aug. 28, 1984, filed July 1, 1983.
The present invention is concerned with an improved valve means or apparatus for controlling the gas or fuel flow to a combustion apparatus or furnace. Specifically, the valve means has an ON/OFF valve and a modulating valve connected in series in a pipe configuration. The valve apparatus has a minimum number of parts and sealing gaskets and is readily connected to a source of gas and an appliance or furnace to which gas is to be controlled.